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Commit b206181d authored by Stefan Haberland's avatar Stefan Haberland Committed by Martin Schwidefsky
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[S390] dasd: add sanity check to detect path connection error 

Prevents possible data corruption by detecting cabling error.
Therefor read and compare the UID for all available channel paths.
Signed-off-by: default avatarStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent e58b0d90
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Showing with 300 additions and 109 deletions
drivers/s390/block/dasd_eckd.c
View file @ b206181d
......@@ -752,24 +752,13 @@ dasd_eckd_cdl_reclen(int recid)
return sizes_trk0[recid];
return LABEL_SIZE;
}
/*
* Generate device unique id that specifies the physical device.
*/
static int dasd_eckd_generate_uid(struct dasd_device *device)
/* create unique id from private structure. */
static void create_uid(struct dasd_eckd_private *private)
{
struct dasd_eckd_private *private;
struct dasd_uid *uid;
int count;
unsigned long flags;
struct dasd_uid *uid;
private = (struct dasd_eckd_private *) device->private;
if (!private)
return -ENODEV;
if (!private->ned || !private->gneq)
return -ENODEV;
uid = &private->uid;
spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
memset(uid, 0, sizeof(struct dasd_uid));
memcpy(uid->vendor, private->ned->HDA_manufacturer,
sizeof(uid->vendor) - 1);
......@@ -792,6 +781,23 @@ static int dasd_eckd_generate_uid(struct dasd_device *device)
private->vdsneq->uit[count]);
}
}
}
/*
* Generate device unique id that specifies the physical device.
*/
static int dasd_eckd_generate_uid(struct dasd_device *device)
{
struct dasd_eckd_private *private;
unsigned long flags;
private = (struct dasd_eckd_private *) device->private;
if (!private)
return -ENODEV;
if (!private->ned || !private->gneq)
return -ENODEV;
spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
create_uid(private);
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
return 0;
}
......@@ -811,6 +817,21 @@ static int dasd_eckd_get_uid(struct dasd_device *device, struct dasd_uid *uid)
return -EINVAL;
}
/*
* compare device UID with data of a given dasd_eckd_private structure
* return 0 for match
*/
static int dasd_eckd_compare_path_uid(struct dasd_device *device,
struct dasd_eckd_private *private)
{
struct dasd_uid device_uid;
create_uid(private);
dasd_eckd_get_uid(device, &device_uid);
return memcmp(&device_uid, &private->uid, sizeof(struct dasd_uid));
}
static void dasd_eckd_fill_rcd_cqr(struct dasd_device *device,
struct dasd_ccw_req *cqr,
__u8 *rcd_buffer,
......@@ -1005,59 +1026,120 @@ static int dasd_eckd_read_conf(struct dasd_device *device)
int conf_len, conf_data_saved;
int rc;
__u8 lpm, opm;
struct dasd_eckd_private *private;
struct dasd_eckd_private *private, path_private;
struct dasd_path *path_data;
struct dasd_uid *uid;
char print_path_uid[60], print_device_uid[60];
private = (struct dasd_eckd_private *) device->private;
path_data = &device->path_data;
opm = ccw_device_get_path_mask(device->cdev);
lpm = 0x80;
conf_data_saved = 0;
/* get configuration data per operational path */
for (lpm = 0x80; lpm; lpm>>= 1) {
if (lpm & opm) {
rc = dasd_eckd_read_conf_lpm(device, &conf_data,
&conf_len, lpm);
if (rc && rc != -EOPNOTSUPP) { /* -EOPNOTSUPP is ok */
DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
"Read configuration data returned "
"error %d", rc);
return rc;
}
if (conf_data == NULL) {
DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
"No configuration data "
"retrieved");
/* no further analysis possible */
path_data->opm |= lpm;
continue; /* no error */
if (!(lpm & opm))
continue;
rc = dasd_eckd_read_conf_lpm(device, &conf_data,
&conf_len, lpm);
if (rc && rc != -EOPNOTSUPP) { /* -EOPNOTSUPP is ok */
DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
"Read configuration data returned "
"error %d", rc);
return rc;
}
if (conf_data == NULL) {
DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
"No configuration data "
"retrieved");
/* no further analysis possible */
path_data->opm |= lpm;
continue; /* no error */
}
/* save first valid configuration data */
if (!conf_data_saved) {
kfree(private->conf_data);
private->conf_data = conf_data;
private->conf_len = conf_len;
if (dasd_eckd_identify_conf_parts(private)) {
private->conf_data = NULL;
private->conf_len = 0;
kfree(conf_data);
continue;
}
/* save first valid configuration data */
if (!conf_data_saved) {
kfree(private->conf_data);
private->conf_data = conf_data;
private->conf_len = conf_len;
if (dasd_eckd_identify_conf_parts(private)) {
private->conf_data = NULL;
private->conf_len = 0;
kfree(conf_data);
continue;
}
conf_data_saved++;
/*
* build device UID that other path data
* can be compared to it
*/
dasd_eckd_generate_uid(device);
conf_data_saved++;
} else {
path_private.conf_data = conf_data;
path_private.conf_len = DASD_ECKD_RCD_DATA_SIZE;
if (dasd_eckd_identify_conf_parts(
&path_private)) {
path_private.conf_data = NULL;
path_private.conf_len = 0;
kfree(conf_data);
continue;
}
switch (dasd_eckd_path_access(conf_data, conf_len)) {
case 0x02:
path_data->npm |= lpm;
break;
case 0x03:
path_data->ppm |= lpm;
break;
if (dasd_eckd_compare_path_uid(
device, &path_private)) {
uid = &path_private.uid;
if (strlen(uid->vduit) > 0)
snprintf(print_path_uid,
sizeof(print_path_uid),
"%s.%s.%04x.%02x.%s",
uid->vendor, uid->serial,
uid->ssid, uid->real_unit_addr,
uid->vduit);
else
snprintf(print_path_uid,
sizeof(print_path_uid),
"%s.%s.%04x.%02x",
uid->vendor, uid->serial,
uid->ssid,
uid->real_unit_addr);
uid = &private->uid;
if (strlen(uid->vduit) > 0)
snprintf(print_device_uid,
sizeof(print_device_uid),
"%s.%s.%04x.%02x.%s",
uid->vendor, uid->serial,
uid->ssid, uid->real_unit_addr,
uid->vduit);
else
snprintf(print_device_uid,
sizeof(print_device_uid),
"%s.%s.%04x.%02x",
uid->vendor, uid->serial,
uid->ssid,
uid->real_unit_addr);
dev_err(&device->cdev->dev,
"Not all channel paths lead to "
"the same device, path %02X leads to "
"device %s instead of %s\n", lpm,
print_path_uid, print_device_uid);
return -EINVAL;
}
path_data->opm |= lpm;
if (conf_data != private->conf_data)
kfree(conf_data);
path_private.conf_data = NULL;
path_private.conf_len = 0;
}
switch (dasd_eckd_path_access(conf_data, conf_len)) {
case 0x02:
path_data->npm |= lpm;
break;
case 0x03:
path_data->ppm |= lpm;
break;
}
path_data->opm |= lpm;
if (conf_data != private->conf_data)
kfree(conf_data);
}
return 0;
}
......@@ -1090,12 +1172,61 @@ static int verify_fcx_max_data(struct dasd_device *device, __u8 lpm)
return 0;
}
static int rebuild_device_uid(struct dasd_device *device,
struct path_verification_work_data *data)
{
struct dasd_eckd_private *private;
struct dasd_path *path_data;
__u8 lpm, opm;
int rc;
rc = -ENODEV;
private = (struct dasd_eckd_private *) device->private;
path_data = &device->path_data;
opm = device->path_data.opm;
for (lpm = 0x80; lpm; lpm >>= 1) {
if (!(lpm & opm))
continue;
memset(&data->rcd_buffer, 0, sizeof(data->rcd_buffer));
memset(&data->cqr, 0, sizeof(data->cqr));
data->cqr.cpaddr = &data->ccw;
rc = dasd_eckd_read_conf_immediately(device, &data->cqr,
data->rcd_buffer,
lpm);
if (rc) {
if (rc == -EOPNOTSUPP) /* -EOPNOTSUPP is ok */
continue;
DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
"Read configuration data "
"returned error %d", rc);
break;
}
memcpy(private->conf_data, data->rcd_buffer,
DASD_ECKD_RCD_DATA_SIZE);
if (dasd_eckd_identify_conf_parts(private)) {
rc = -ENODEV;
} else /* first valid path is enough */
break;
}
if (!rc)
rc = dasd_eckd_generate_uid(device);
return rc;
}
static void do_path_verification_work(struct work_struct *work)
{
struct path_verification_work_data *data;
struct dasd_device *device;
struct dasd_eckd_private path_private;
struct dasd_uid *uid;
__u8 path_rcd_buf[DASD_ECKD_RCD_DATA_SIZE];
__u8 lpm, opm, npm, ppm, epm;
unsigned long flags;
char print_uid[60];
int rc;
data = container_of(work, struct path_verification_work_data, worker);
......@@ -1112,64 +1243,129 @@ static void do_path_verification_work(struct work_struct *work)
ppm = 0;
epm = 0;
for (lpm = 0x80; lpm; lpm >>= 1) {
if (lpm & data->tbvpm) {
memset(data->rcd_buffer, 0, sizeof(data->rcd_buffer));
memset(&data->cqr, 0, sizeof(data->cqr));
data->cqr.cpaddr = &data->ccw;
rc = dasd_eckd_read_conf_immediately(device, &data->cqr,
data->rcd_buffer,
lpm);
if (!rc) {
switch (dasd_eckd_path_access(data->rcd_buffer,
DASD_ECKD_RCD_DATA_SIZE)) {
case 0x02:
npm |= lpm;
break;
case 0x03:
ppm |= lpm;
break;
}
opm |= lpm;
} else if (rc == -EOPNOTSUPP) {
DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
"path verification: No configuration "
"data retrieved");
opm |= lpm;
} else if (rc == -EAGAIN) {
DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
if (!(lpm & data->tbvpm))
continue;
memset(&data->rcd_buffer, 0, sizeof(data->rcd_buffer));
memset(&data->cqr, 0, sizeof(data->cqr));
data->cqr.cpaddr = &data->ccw;
rc = dasd_eckd_read_conf_immediately(device, &data->cqr,
data->rcd_buffer,
lpm);
if (!rc) {
switch (dasd_eckd_path_access(data->rcd_buffer,
DASD_ECKD_RCD_DATA_SIZE)
) {
case 0x02:
npm |= lpm;
break;
case 0x03:
ppm |= lpm;
break;
}
opm |= lpm;
} else if (rc == -EOPNOTSUPP) {
DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
"path verification: No configuration "
"data retrieved");
opm |= lpm;
} else if (rc == -EAGAIN) {
DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
"path verification: device is stopped,"
" try again later");
epm |= lpm;
} else {
dev_warn(&device->cdev->dev,
"Reading device feature codes failed "
"(rc=%d) for new path %x\n", rc, lpm);
continue;
}
if (verify_fcx_max_data(device, lpm)) {
epm |= lpm;
} else {
dev_warn(&device->cdev->dev,
"Reading device feature codes failed "
"(rc=%d) for new path %x\n", rc, lpm);
continue;
}
if (verify_fcx_max_data(device, lpm)) {
opm &= ~lpm;
npm &= ~lpm;
ppm &= ~lpm;
continue;
}
/*
* save conf_data for comparison after
* rebuild_device_uid may have changed
* the original data
*/
memcpy(&path_rcd_buf, data->rcd_buffer,
DASD_ECKD_RCD_DATA_SIZE);
path_private.conf_data = (void *) &path_rcd_buf;
path_private.conf_len = DASD_ECKD_RCD_DATA_SIZE;
if (dasd_eckd_identify_conf_parts(&path_private)) {
path_private.conf_data = NULL;
path_private.conf_len = 0;
continue;
}
/*
* compare path UID with device UID only if at least
* one valid path is left
* in other case the device UID may have changed and
* the first working path UID will be used as device UID
*/
if (device->path_data.opm &&
dasd_eckd_compare_path_uid(device, &path_private)) {
/*
* the comparison was not successful
* rebuild the device UID with at least one
* known path in case a z/VM hyperswap command
* has changed the device
*
* after this compare again
*
* if either the rebuild or the recompare fails
* the path can not be used
*/
if (rebuild_device_uid(device, data) ||
dasd_eckd_compare_path_uid(
device, &path_private)) {
uid = &path_private.uid;
if (strlen(uid->vduit) > 0)
snprintf(print_uid, sizeof(print_uid),
"%s.%s.%04x.%02x.%s",
uid->vendor, uid->serial,
uid->ssid, uid->real_unit_addr,
uid->vduit);
else
snprintf(print_uid, sizeof(print_uid),
"%s.%s.%04x.%02x",
uid->vendor, uid->serial,
uid->ssid,
uid->real_unit_addr);
dev_err(&device->cdev->dev,
"The newly added channel path %02X "
"will not be used because it leads "
"to a different device %s\n",
lpm, print_uid);
opm &= ~lpm;
npm &= ~lpm;
ppm &= ~lpm;
continue;
}
}
/*
* There is a small chance that a path is lost again between
* above path verification and the following modification of
* the device opm mask. We could avoid that race here by using
* yet another path mask, but we rather deal with this unlikely
* situation in dasd_start_IO.
*/
spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
if (!device->path_data.opm && opm) {
device->path_data.opm = opm;
dasd_generic_path_operational(device);
} else
device->path_data.opm |= opm;
device->path_data.npm |= npm;
device->path_data.ppm |= ppm;
device->path_data.tbvpm |= epm;
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
}
/*
* There is a small chance that a path is lost again between
* above path verification and the following modification of
* the device opm mask. We could avoid that race here by using
* yet another path mask, but we rather deal with this unlikely
* situation in dasd_start_IO.
*/
spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
if (!device->path_data.opm && opm) {
device->path_data.opm = opm;
dasd_generic_path_operational(device);
} else
device->path_data.opm |= opm;
device->path_data.npm |= npm;
device->path_data.ppm |= ppm;
device->path_data.tbvpm |= epm;
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
dasd_put_device(device);
if (data->isglobal)
......@@ -1441,11 +1637,6 @@ dasd_eckd_check_characteristics(struct dasd_device *device)
device->default_expires = value;
}
/* Generate device unique id */
rc = dasd_eckd_generate_uid(device);
if (rc)
goto out_err1;
dasd_eckd_get_uid(device, &temp_uid);
if (temp_uid.type == UA_BASE_DEVICE) {
block = dasd_alloc_block();
......
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